Display panels comprising large numbers of light-producing cells, particularly gas-filled cells, have been known in the art for some time. However, up to the present time, the necessary inventions have not been made to convert these devices from the theoretical or laboratory state to the practical commercial state. In gas-filled devices which are intended to be caused to glow to display characters, a voltage is applied across selected cells to provide the desired breakdown and glow. The breakdown and glow-producing process is generally considered to require the presence in the gas of at least one electron to initiate the required collisions and energy interchanges which produce glow.
The initiating electron(s) are not, relatively speaking, easy to obtain, but they can be obtained, for example, by field emission or photoemission. However, these methods are not sufficiently fast or easy to carry out when it is desired to enter and change information in a display panel at relatively high speed.